(1) Field of the Invention
The present invention relates to an insect-proofing agent and an insect-proofing method. More specifically, the present invention relates to an insect-proofing agent comprising trioxane as the active ingredient and an insect-proofing method using trioxane.
(2) Description of the Prior Art
p-Dichlorobenzene, naphthalene and camphor have been used as sublimable insect-proofing agents, and these compounds are widely used as insect-proofing agents for preventing damage to articles of clothing, caused for example by a case making clothes moth a webbing clothes moth a varied carpet beetle and a black carpet beetles. Among these compounds, p-dichlorobenzene has a large insecticidal force and has an immediate effect and is therefore mainly used as the household moth-proofing agent.
The following properties are ordinarily required for moth-proofing agents. Namely, a moth-proofing effect is manifested in an application space for a long time, ordinarily for several months, no toxicity is given to human bodies and no unpleasant feeling is given. p-Dichlorobenzene is most frequently used as the moth-proofing agent satisfying these requirements tolerably, and in order to moderate the inherent irritating odor of p-dichlorobenzene, a perfume or the like is incorporated. However, recently, environmental contamination with p-dichlorobenzene is becoming a social problem. Namely, p-dichlorobenzene, as well as polychlorobiphenyl (PCB), is an aromatic chlorine compound and has an unnecessarily high stability and is hardly decomposable. Therefore, the environmental residual property is very high. According to certain investigations, p-dichlorobenzene was detected not only in houses but also in vacant lands or thickets of assorted trees 80 m apart from houses. Furthermore, p-dichlorobenzene is one of target substances for general inspection of safety of chemical substances specified by the Environmental Agency. Furthermore, it is said that p-dichlorobenzene causes liver troubles, lung granulomata, cataract and dermatitis.
In addition, p-dichlorobenzene as the moth-proofing agent is defective in that since p-dichlorobenzene contains chlorine atoms in the molecule, metallic decoration for clothes such as gold and silver threads (composed of brass, aluminum and the like) and spangles are often blackened. In order to obviate this disadvantage, naphthalene or camphor has been used. However, since the sublimation speed of naphthalene or camphor is low, naphthalene or camphor is not suitable for a preservation box which is often opened and closed. Also naphthalene is an aromatic compound, and the toxicity and residual property are comparable to those of p-dichlorobenzene. Moreover, naphthalene has a peculiar odor stronger than that of p-dichlorobenzene.
Conventional use of an insect-proofing agent is not limited to prevention of damages of clothes by moths or insects but it is required to use an insect-proofing agent in other fields. Namely, when people remain outdoors, for example, at a picnic, hiking, garden party or an athletic meeting, or the like, thus can come into contact with ants, ground beetles, shield bugs and other insects and it is often experienced that unpleasant feeling are given. Moreover, in the fields or in houses, people may be stung by ants or foods may be damaged by gathering moths or insects. An insect-proofing agent effective for preventing such damage has hardly been developed. For example, an immediate effect insecticide often used at home shows a temporary controlling action but since the insecticide is promptly volatilized off, the controlling action is not durable. Moreover, it is not the insecticidal action but the insect-proofing action that is required. Namely, it is sufficient that insects or moths are expelled, and insects or moths need not be killed. In case of a delayed effect insecticide, the action is not immediately obtained, and the residual property is ordinarily strong and environmental contamination is caused. A repellent to be applied to the human skin is insufficiently small in the effect-extending region. Moreover, these conventional agents are ordinarily oil-soluble and they are used in the form of preparations which are more or less combustible. Accordingly, use of these agents near a fire, such as an open-air fire, or a portable cooking stove, is very dangerous.